repairs to phone under guarantee

Phone was received in November 2013 with a two year guarantee. We took the phone in for repair on the 10th April 2015. On the 10th i received an sms to call regarding the phone and was told that the battery is not covered by the guarantee but that the other repairs are. I agreed to pay for the battery. Today when I received the phone I see I was charged for the battery and labour. I am upset that I was charged labour when the phone is still under guarantee.